1. Field of the Invention
The present invention relates to a new metallic modified material having the same chemical composition as an intermetallic compound semiconductor but differing in crystalline structure and a process for the production of the same.
2. Description of the Prior Art
As an intermetallic compound semiconductor, there are known Group III-V compounds having a zincblende-type or wurtzite-type crystalline structure such as InSb, InAs, InP, GaSb, GaAs, GaP, etc., Group II-VI compounds such as ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, BeO, etc., Group I-VII compounds such as CuCl and Group IV-VI compounds having a rocksalt type crystalline structure such as PbS, PbSe, PbTe, SnTe, etc. On the other hand, it is known that amorphous semiconductors of intermetallic compounds are formed on substrates by vacuum deposition method or by sputtering method. When intermetallic compound semiconductors are exposed to a high pressure at room temperature, for example, InSb, GaSb, AlSb, etc. are transformed into a white-tin-type crystalline structure and InAs, InP, ZnSe, ZnTe, CuCl, etc. are transformed into a rocksalt type crystalline structure, thus behaving themselves like a metal. However, phase transition into the semiconductor phase takes place when the pressure is lowered to normal pressure. It is also known that the high pressure metallic phase of Group III-V compounds is obtained as a metastable phase when the pressure is lowered to normal pressure at 77.degree. K.
The inventors have previously reported that an amorphous InSb semiconductor is transformed into a material of rocksalt-type crystalline structure under a high pressure such as of about 10 Kbar, which is further transformed into a material of white-tin-type crystalline structure under a high pressure such as about 30 Kbar and which is transformed into a mixture of zincblende-type crystalline structure and rocksalt-type crystalline structure when the pressure is lowered to normal pressure. Thus, this is unstable under high pressures.